Nozzle bleed



NOV. 12, 1963 ROMEO 3,110,750

NOZZLE BLEED Filed Feb. 20. 1961 INVENTOR. NEIL M. ROMEO BYw' ATTORNEYS United States Patent 3,119,750 NGZZLE ELIEED Neil M. Romeo, St. Clair Shores, Mich, assignor to Holley Carburetor (Iompany, Warren, Mich, a corporation of Michigan Filed Feb. 20, 1961, Ser. No. 90,299 8 Claims. (Ci. 261--'72) The invention relates to fuel and air mixing and discharge systems and refers more specifically to carburetor fuel and air mixing and discharge systems for use with internal combustion engines or similar devices having a main discharge nozzle including an air bleed.

in the past fuel and air mixing and discharge systems of carburetors for use :with internal combustion engines and similar devices have provided means for mixing the fuel in the main fuel wells with air from a main air bleed before it is passed to the main discharge nozzle. The fuel and air mixture has in the past been dischmged from the main discharge nozzle without further mixing of air With the semi-homogeneous fuel and air mixture. With such systems the fuel and air mixture leaving the main discharge nozzle contains small droplets of raw fuel which are not mixed with air whereby proper fuel utilization is not accomplished by the utilizing device.

Therefore it is an object of the present invention to provide a main discharge nozzle in a fuel and air mixing and discharge system which includes means to more completely mix the fuel discharged therefrom with air.

Another object is to provide a main discharge nozzle in a fuel and air mixing and discharge system which includes an air bleed passage.

Another object is to provide a carburetor including a main fuel well extending into the carburetor fuel bowl chamber and receiving fuel therefrom, a main air bleed for bleeding air into the main fuel well whereby the air is mixed with the fuel, means for passing the fuel and air mixture to a main discharge nozzle, and a second air bleed in the main discharge nozzle for bleeding additional air into the main discharge nozzle for mixing the fuel and air mixture with additional air before it is discharged from the main discharge nozzle.

Another object is to provide a carburetor including a carburetor fuel bowl chamber, a main fuel well within the carburetor fuel bowl chamber, a main metering jet for metering fuel into the main fuel well, a main well tube within the main well and opening into the fuel in the main well, a main air bleed communicating with the main well tube for bleeding air through the main well tube into the main well for mixing with the fuel in the main Well, a chamber for storing the fuel and air mixture before passage of the mixture to the main discharge nozzle, a passage between said chamber and the main discharge nozzle and an air bleed at the main discharge nozzle in communication with the passage to mix further it with the fuel and air mixture passing from the chamber to the main discharge nozzle.

Another object is to provide a fuel and air mixing and discharge system as set forth above wherein the nozzle air bleed comprises a passage extending transversely of the passage between the chamber and main discharge nozzle and in communication with the choke side of the main discharge nozzle at one end and with the passage between the chamber and main discharge nozzle at the other.

Another object is to provide a fuel and air mixing and discharge system as set forth above wherein the nozzle air bleed comprises a bleed tube extending from the choke side of the main dischange nozzle into the passage be- 3,llh,75 Patented Nov. 12, 1963 tween the chamber and main discharge nozzle a predetermined distance.

Another object is to provide a nozzle air bleed in a fuel mixing and discharge system as set forth above which is simple in construction, economical to manufacture and efficient in use.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, illustrating a preferred embodiment of the invention, wherein:

FIGURE 1 is an elevation view partly in cross section of a carburetor including a fuel and air mixing and discharge system having a nozzle air bleed in accordance with the invention.

FIGURE 2 is an enlarged section View of the main discharge nozzle and nozzle air bleed of the fuel and air mixing and discharging system illustrated in FIGURE 1.

FlGURE 3 is a section view of a main discharge nozzle similar to that shown in FIGURE 2 and particularly 'l'l-ustrating a modified nozzle air bleed.

With particular reference to the figures of the drawing, one embodiment of the invention will now be disclosed.

in accordance with the invention the carburetor ill which is mounted on the internal combustion engine 12 is provided with a fuel mixing and discharge system 14. The fuel mixing and discharge system 14 includes the main discharge nozzle 16 having the air bleed 18 in conjunction therewith for mixing additional air with the fuel discharged from nozzle 16.

In operation fuel passing to the main discharge nozzle 16 through the passage 20 which has been previously mixed with air from the main air bleed passage 22 is further mixed with air from the air bleed 18 so that the fuel and air mixture discharged from the main discharge nozzle 16 is more nearly homogeneous.

More specifically the carburetor 10 includes the housing 24- including the carburetor fuel bowl chamber 26 therein in which fuel is stored before being discharged into the air intake passage 28 of the carburetor, the throttle valve fill and choke ualve 32. mounted in the air intake passage 22* Also, as previously indicated, the fuel and air mixing and discharge system 14 is included in the carburetor it).

The fuel and air mixing and discharge system 14 includes the main fuel well 34 positioned Within the carburetor fuel bowl chamber 25 as illustrated in FIGURE 1 and a main metering jet 36 threaded in the end Sid of the main well 34. The main metering jet 3 6 is operable to meter fuel from the carburetor fuel bowl chamber 26 into the main metering well 34 in accordance with engine requirements.

A main well tube 4% is suspended from the other end 4 1 of the main well 34, as illustrated in FIGURE 1. The main W611 tube 4% is closed at end 42. and is open at end 44 in communication with chamber 46 and the main air bleed passage 2% through opening 43 in gasket 49. The transverse passages fit are provided in the main Well tube ill as shown to connect the main air bleed passage 22 with the interior of the main well 34 as shown.

The main well 34 is further connected with the chamber 52 through passage 5- at the end 41 of the main well 34, as shown in FIGURE 1. Chamber 52 is connected to the main discharge nozzle 16 through the passage 20 as previously indicated.

In operation of a fuel and air mixing and discharge system as thus far described fuel is metered into the main well 34 through the metering jet 36 which fuel is mixed 3 with air from the air bleed passage 22 in the main well 34*. The partially homogeneous mixture is then drawn through the passage 5d into chamber 52 where it remains until it is subsequently drawn through the passage 20 and discharged into the air intake passage 2% of the carburetor through the main discharge nozzle '16. With such operation the air fuel mixture passing through passage is not fully homogeneous but contains small droplets of raw fuel which are not mixed with the air.

Therefore, in accordance with the invention, a nozzle air bleed lb provided to further mix the air fuel mixture in passage 2% with additional air so that the air fuel mixture passing from the nozzle 15 into the air passage is more homogeneous. The nozzle air bleed, as shown in FlGURES l and 2, comprises a passage extending from the passage 2% at one end to the choke side of the inner surface 53 of the main discharge nozzle 16.

A modification of the improved main discharge nozzle structure of the invention is shown in PlGURE 3. in the modified structure the nozzle air bleed comprises a bleed tube 68* extendin through the passage 1.3a in the main discharge nozzle 16a. The bleed tube so as shown is adjustable transversely of passage Ella by convenient means such as the threaded connecton between the tube so and passage lila illustrated in FIGURE 3 and may be extended as far as desirable into the passage Zila to bleed a desired amount of air into the air fuel mixture in the passage Zlla. The farther into the passage 23:: that the tube 6% extends the less air will be bled through the tube of: into the passage 2% and the richer the fuel air mixture discharged from the passage Zlla into the main discharge nozzle 16a and air intake passage of the carburetor will be.

Thus it will be seen that in accordance with the invention a nozzle air bleed is provided in conjunction with the main discharge nozzle of a fuel and air mixing and discharge system of a carburetor whereby a more homogeneous fuel air mixture is delivered to the air intake passage of the carburetor.

The drawings and the foregoing specification constitute a description of the improved fuel and air mixing and discharge system in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What l claim as my invention is:

1. In a fuel and air mixing and discharge system, a chamber into which fuel partly mixed with air is drawn, a nozzle for discharging an air fuel mixture, at discharge passage extending between said chamber and nozzle through which the partly mixed fuel and air is transferred from the chamber to the nozzle, an air bleed passage extending between a source of air and the discharge passage, and an axially adjustable bleed tube secured in the air passage and extending into the discharge passage an adiustable distance operable to bleed air into the discharge passage to more fully mix the fuel in the discharge passage with air before it is discharged from the nozzle.

2. A fuel and air mixing and discharge system in a carburetor having a. carburetor fuel bowl and an air intake passage, comprising a main fuel well suspended in the fuel bowl, a fuel metering jet for metering fuel into the main fuel well from the carburetor fuel bowl, a main fuel well tube suspended within and in spaced relation radially to the mm'n fuel well in communication interiorly with a source of air and having transverse passages therethrough whereby air is admitted into the main fuel well to provide a raw fuel and air mixture in the main fuel well, a hollow cylindrical fuel discharge nozzle having an axially convex radially inner surface suspended within the air intake passage of the carburetor, a chamber between the main fuel well and nozzle, a first passage for transferring the raw fuel and air mixture from the main fuel well into said chamber, a second passage extending between said chamber and the interior of the cylindrical fuel nozzle for transferring fuel between the chamber and nozzle and an air bleed passage extending transversely of the second passage betwee the inner surface of the nozzle and the second passage for bleeding air into the second passage whereby the fuel and air mixture therein is further mixed with additional air before it is discharged from the nozzle.

3. A fuel and air mixing and discharge system in a carburetor having a carburetor fuel bowl and an air intake passage, comprising a main fuel Well suspended in the fuel bowl, a fuel metering jet for metering fuel into the nain fuel well from the carburetor fuel bowl, a main fuel well tube suspended within and in spaced relation radially to the main fuel well in communication interiorly with a source of air and having transverse passages there through whereby air is admitted into the main fuel well to provide a raw fuel and air mixture in the main fuel well, a hollow cylindrical fuel discharge nozzle having an axially convex radially inner surface suspended within the air intake passage of the carburetor, a chamber between the main fuel well and nozzle, a first passage for transferring the raw fuel and air mixture from the main fuel well into said chamber, a second passage extending between said chamber and the interior of the cylindrical fuel nozzle for transferring fuel between the chamber and nozzle, an air bleed passage extending transversely of the second passage between the inner surface of the nozzle and the second passage, a sleeve having a restriction therein threadedly received in the air bleed passage and adjustable axially therein so that one end thereof is positioned a variable distance into the second passage for bleeding air into the second passage whereby the fuel and air mixture therein is further mixed with additional air before it is discharged from the nozzle.

4. A carburetor having an air intake passage and including a fuel bowl, a fuel well extending into the fuel bowl, means for metering fuel from the fuel bowl into fuel well, a main air leed for bleeding air into said fuel well for mixing with the fuel therein, a chamber adjacent the fuel well, a transfer passage between the fuel well and chamber for transferring partly mixed air and fuel from the fuel well to the chamber, a nozzle located within the carburetor air intake passage for discharging mixed air and fuel thereinto, said nozzle being a hollow cylinder extending axially parallel to the carburetor air intake passage and having an axially convex inner surface, a discharge passage extending transversely into the interior of the nozzle centrally thereof and between said chamber and nozzle through which the partly mixed fuel and air is transferred from the chamber to the nozzle and an air bleed passage extending between the inner surface of the nozzle near the end of the nozzle closest the carburetor air intake and the discharge passage in direct communication with the discharge passage operable to bleed air into the discharge passage to more fully mix the fuel in the discharge passage with air before it is discharged from toe nozzle.

5. Structure as claimed in claim 4 and further including a tube secured in the air bleed passage extending into the discharge passage through which the air bleeds into the discharge passage.

6. Structure as claimed in. claim 5 wherein the tube is threaded into the air bleed passage to permit adjusting the distance which the tube extends into the discharge passage.

7. in a fuel and air mixing and discharge system, a main fuel well for mixing fuel and air fed thereto, an air intake passage, a hollow nozzle positioned within the air intake passage and having an axially convex radially inner surface, a discharge passage extending between the main fuel well and nozzle for transferring the air fuel mixture to the nozzle and an air bleed passage extending between the inner surface of the nozzle on the air intake side of the air intake passage and the discharge passage in direct communication with the discharge passage between the ruel well and the nozzle end of the discharge passage operable to bleed air into the air fuel mixture in the discharge passage to more fully mix the fuel in the discharge passage with air before it is discharged from the nozzle.

8. Structure as set forth in claim 7 and further including a sleeve having a restriction therein threaded in the air bleed passage for adjustment transversely of and extending into the discharge passage wherein the radial position within the discharge passage at which additional air is bled into the discharge passage is adjustable.

' References Citedjn the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Great Britain Mar. 15, 1944 

4. A CARBURETOR HAVING AN AIR INTAK E PASSAGE AND INCLUDING A FUEL BOWL, A FUEL WELL EXTENDING INTO THE FUEL BOWL, MEANS FOR METERING FUEL FROM THE FUEL BOWL INTO THE FUEL WELL, A MAIN AIR BLEED FOR BLEEDING AIR INTO SAID FUEL WELL FOR MIXING WITH THE FUEL THEREIN, A CHAMBER ADJACENT THE FUEL WELL, A TRANSFER PASSAGE BETWEEN THE FUEL WELL AND CHAMBER FOR TRANSFERRING PARTLY MIXED AIR AND 